BEGIN:VCALENDAR
CALSCALE:GREGORIAN
PRODID:iCalendar-Ruby
VERSION:2.0
BEGIN:VEVENT
DESCRIPTION: In this lecture I will give an introduction to algebraic and s
 emi-algebraic methods for proving the unsatisfiability of systems of real p
 olynomial equations over the Boolean hypercube. The main goal of this talk 
 is to compare the relative strength of these approaches using methods from 
 proof complexity.    On the one hand\, I will focus on the static semi-alge
 braic proof systems Sherali-Adams and sum-of-squares (a.k.a. Lasserre)\, wh
 ich are based on linear and semi-definite programming relaxations. On the o
 ther hand\, I will discuss polynomial calculus\, which is a dynamic algebra
 ic proof system that models Gröbner basis computations.    I am going to pr
 esent two recent results on the relative strength between algebraic and sem
 i-algebraic proof systems:¹    The first result is that sum-of-squares simu
 lates polynomial calculus: any polynomial calculus refutation of degree d c
 an be transformed into a sum-of-squares refutation of degree 2d and only po
 lynomial increase in size. In contrast\, the second result shows that this 
 is not the case for Sherali-Adams: there are systems of polynomial equation
 s that have polynomial calculus refutations of degree 3 and polynomial size
 \, but require Sherali-Adams refutations of large degree and exponential si
 ze.    ¹) this work was presented at STACS 2018\; a preprint is available a
 t   https://eccc.weizmann.ac.il/report/2017/154/   
DTSTAMP:20181108T142800
DTSTART:20181112T141500
CLASS:PUBLIC
LOCATION:Humboldt-Universität zu Berlin\n Institut für Informatik\n Humbold
 t-Kabinett (between House 3&amp;4 / 1st Floor [British Reading])\n Johann von N
 eumann-Haus\n Rudower Chaussee 25\n 12489 Berlin
SEQUENCE:0
SUMMARY:Christoph Berkholz (Humboldt-Universität zu Berlin): A comparison o
 f algebraic and semi-algebraic proof systems
UID:94442671@/www.mi.fu-berlin.de
URL:https://www.mi.fu-berlin.de/en/facetsofcomplexity/monday/20181112-L-Ber
 kholz.html
END:VEVENT
END:VCALENDAR
